It is known that on subjecting humans or certain mammals (e.g. dogs, cats) to long-lasting external moving or transportation accompanied by unusual or special movements (such as shaking, waving, unusual atmospheric conditions, great acceleration, uneven road conditions, etc.) characteristic undesired and unfavorable physiological symptoms occur.
The above symptoms are generally called "sea disease" or "air sickness" ("nausea maris", kinetosis, car-sickness, etc.). This is however no real disease but a physiological symptom complex which occurs with humans under certain conditions. The symptoms depend on the individual and his (or her) antecedents, training, habits and biological condition. The symptoms can be observed mainly portation in air or sea travel but in case of certain persons they occur also when travelling by motorcar, bus, train or riding, in an elevator, on a cable railway, etc.
It is unnecessary to discuss the disadvantages of this condition in details. Persons driving in heavy traffic are very often subjected to this condition which is extremely disadvantageous and dangerous in cases when the person has to work during transport or traffic or soon afterwards. Thus vehicle drivers, air pilots, spacemen, astronauts, aircraft staff members or sportsmen, commercial travellers, businessmen, etc. who must exhibit high-level and concentrated intellectual or physical activity are badly in need of the prophylaxis of "kinetosis". This need has so far not been duly satisfied.
Similarly there is a demand for the prophylaxis of undesired symptoms which occur on the transportation of mammal animals (e.g. hygienic transportation of animals, etc. after the termination of transportatio etc.).
Compositions comprising scopolamine (L-6,7-epoxy-tropine-tropate) were the first preparations used for the propylaxis of sea-sickness. This alkaloid is however a strong parasympatholytic which causes visual disturbances, stupor, muscular weakness, dryness of mouth and the use thereof is dangerous. Recently attempts have made to eliminate certain undesired side effects of scopolamine by administering the same intradermally (Aviat, Space Environ. Med. 54 (II) pages 984-1000).
The other generally used composition (Dymenhydrinate.sup.x) comprises the 8-chloro-theophyllin salt of N,N-dimethyl-2-(diphenylmethoxy)-ethyl-amine as active ingredient (Daedalon.sup.R ; J. Am. Med. Assn. 160, pages 755-760). The use of this composition involves fewer hazards but the said composition exhibits very unfavorable hypnotic sedative effects. Daedalon effects working capacity and performance during transportation or thereafter in an undesired manner, and moreover in certain cases makes the same even impossible.
It is known furtheron that Cavinton.sup.R (comprising as active ingredient Vinpocetin.sup.x) decreases the affinity for kinetosis (Bodo, Hartman: Therapia Hungarica 27.2 (1979.)). The drawback of Cavinton.sup.R is that the effect is exerted only 5-7 days after administration.
The basic factors of the neurophysiology of the kinetosis are as follows:
The vestibular receptor, the retina and the somatosensorial receptors are unusually stimulated by the movement and weightlessness. The various structures react pathologically upon the unusual stimuli in the central nervous system. The reaction of the CNS is vertigo, nausea, head-ache and sleepiness. The reaction of the limbic system results in depression. The hypothalamus induces through the hypophysis an increased production of ADH, ACTH, GH, PRL. The vestibular cerebellum causes through the vegetative nervous system cold sweat, pallor, reduced stomach motility and cardiovascular and respiratory disorder. the vestibular cerebellum causes vomiting as well due to Parvicellularis Reticularis Formatio (Brain Res. 270: 154-158.)
The point of attack of drugs acting against kinetosis has not been determined exactly. Effective agents are the centrally attacking anticholinergic hyoscin and the adrenergic ephedrine and amphetamine. The activity of the phenothiazine blocking dopamine D.sub.2 receptors in the chemoreceptor trigger zone is very weak. Effective preventing agents are other antihistamines, such as dimenhydrinate, cyclizin and cinnarizene. As a peripherally acting agent domperidon can be mentioned.